Type bar cushioning pad



Sept. 21, 1943.

G. PREZIOSQ TYPE BAR CUSHIONING PAD Filed Aug. 7, 1941 m N m M Gizwep ve Bezcb 5% v a V 9761?: s

Patented Sept. 21, 1943 TYPEBARICUSHIONING rang Giuseppe Prezioso,Yverdon, Switzerlani assignor' to E. Paillard et Cie A., Yverdon, Switzer- 1 land, a corporation of Switzerland I i ApplicationAugust 7,1941, Serial No. 405,874

' l 'In'Switzerland September 2, 1940 V l Claims." (01. 197- 42) d in d v v companying drawing which illustrates embodi- Typewriters of modern typemust fulfill a number of requirements which are-often in contradistinction with one another such for example as noiselessness and speed. One of the principal causes of noise or" rattle in a typewriter is due to the impact of the type bars upon theircarrier. The noise thus produced naturally increases as the touch grows taster. Inorde'r toeliminate such noise, it has: been previouslyproposed to' line the carrier for the typebars with a coating of a resilient material such as indiarubber, felt or the like. However,

ble itis to obviate the noise produced by the sharp impact of the type bars as they fall back to-their position of rest, the greater their tend-- en-cy to rebound. This rebounding action soon grows large enough to make it impossibleto-continuegto typewrite' even at normal-speed as the thus rebounding type bars soon become en-tan-- gled. In view of this, a compromise solution was adopted hitherto consisting in'eithersacrificing to noiselessness' or 'conv'erse ly noiselessness to rapidity depending ripon the kind of typewriter and thepurpos'e for which used. It has also been prorapidity of operation it is intended to be posed to support the lining made of resilient material by'elastic members permitting said lining to be shifted longitudinally. However, the result that was thus sought failed to be attained. Moreover, linings comprising a metal core imbedded in a pliable or elastic covering did not meet the requirements either.

An object of the present invention is to provide an improved pad or cushion for the type bars of typewriters, said pad having such a construction as to substantially attenuate the noise or rattle that they would otherwise produce when swinging back to their position of rest after striking the ribbon against the paper sheet on the platen without,' however, rebounding to any appreciable extent and giving rise to any risk of the type bars becoming entangled or gripping one another.

Another object of the inventionis to provide an improved impact-taking pad or cushion of this character having such a structure as to lend itself to repeated resilient distortions without sing its operative shape and cushioning capacity even after prolonged use.

With these and such other objects in view as will incidentally appear hereinafter, the invention consists in the novel construction, combination and arrangements of elements that will now be described in detail with reference to the acthe more resilient the 1ining thus fitted or in-other WOIdsthemo-re 'capa ted byany of the procedures ments of the invention. I a

In the drawing: n k Figure 1' is a diagrammatic front view showing a form of the cushioning pad inoperative'posi-1 tion on its" carrier/the type I shape'whoseimpact must betalren by thispad not I being" illustrated.

Figured is asectional" view the line -II-"-II ofFigl." w w I Figure 3 isa viewsimilar Figllsho wing an alternative constructional form "of the pad and carrier assembly; i R

Figure 4 is a sectionalview on the line IV-IV. of Fig. 3; As illustrated in Figs. 1 and 2,-an"upstan'ding arcuate carrier member. or plate I: made forex ample or sheet metal and rigidly'secured-iniany approved way-J to thegtypewriter 'frame =(no't shown) is providedwith end eye-shaped brack etsv 2 and with a trough-shaped portion 3* in the; middle of its length." The brackets. Z'are adapted tov girdle and clamp the-pad or cushion l at or adjacent its-respective ends while leaving it free to resilientlyyield'over substantially the whole of its length. The purpose of the trough-shapedv portions is merely to guide" the padnand to hold itinthe reduiredlocation so as toprevent the same from swinging or swaying. The pad 4 is advantageously constituted by an elongated body of tubular or hose-like shape made of any suitable pliable or supple substance.

In the alternative-constructional form shown in Figs. 3 and 4, the elongated pad or cushion 4 extends beyond the ends of the carrier member I and the latter is fitted with trough-shaped brackets or clips 5 which do not girdle the pad 4 around the whole of its peripheral outline. Proper attachment of the pad in the holding brackets or clips 5 may able means and particularly by any convenient procedure capable of causing their matching or contiguous surfaces to remain adherent or-coalescent, for example by a curing, cementing, sticking or vulcanizing process, as is well known in the art. In this constructional form, the elongated tubular 0r hose-like pad 4 is internally fitabove mentioned with an arcuate rod-like or wire-like core 6 having the same radius. of curvature of the pad, said rod also having stiffening properties and a cross sectional area smaller than that of the hollow portion of the pad.

Advantageously the core 6 is a pre-shaped metal rod, rope or wire whilethe tubular pad 4 bars ot conventional be performed by any suitmay be made either of a homogeneous material such as pure rubber or latex or else of a composite or laminated material such for example as natural or artificial rubber in which canvas or buckram is imbedded or inlaid, felt or any other pliant substance utilisable in the art.

An important purpose of the stiffening core 6 is to preserve the useful shape of the pad 4 notwithstanding the innumerable shocks due to the ever repeated impacts of the type bars that recoil at each operative stroke when typewriting. As the core 6 has a smaller cross sectional shape than the inner section of the tubular pad 4, it provides between their'contiguous surfaces a free space or clearance which contributes to give to the pad adequate suppleness and resiliency.

As will be understood, in order to eliminate any noise caused by the impact of the type bars on their carrying surface, it is necessary that somehow the latter should become momentarily distorted and that the energy which is thus imparted to said carrying surface should not be given back to the type bars but absorbed as completely as possible by its resilient distortion and.

by itsresumption of its normal shape.

Owing to' the fact that the improved pad is supported and held at a few points only, the aforesaid requirement is primarily fulfilled because any local distortion of the pad is converted into a longitudinal distortion which is evenly distributed throughout its length or at least over an appreciable length on both sides of the pacting type bar. Such a distortion absorbs a substantial proportion of the energy of said type bar which cannot therefore be imparted back to said bar. Furthermore by providing a free clearance or space inside the pad, such an action is still further enhanced because to the longitudinal distortion thus evenly distributed there is added an evenly distributed transverse distortion.

A cushioning pad having the aforesaid struc-V ture may be adapted either to new typewriters or to existing typewriters for example as a substitution for the type bar carrier lining of known form.

The constructional details may vary without departing from the scope of the subioined claims.

What is claimed is:

l. A shock and sound absorbing unit for cushioning the rebound of the type bars of typewriters, comprising, an attaching plate having a horizontally straight bottom portion provided at its corners with fastening receiving openings and adapted to be secured to the typewriter frame in a vertical plane, said plate having its upper portion formed with an arcuate edge, cushion supporting elements formed integrally with the plate at the ends of the arcuate upper edge and offset rearwardly of the vertical plane of the body, an intermediate cushion supporting member formed integrally with th lower portion of the arcuate edge of the plate and offset forwardly of the vertical plane of the body, and an arcuate cushioning pad mounted on said rearwardly and forwardly extending cushion supporting elements respectively at the ends and intermediate portion of the arcuate edge of the plate thereby to support the cushioning pad at an oblique angle to'the vertical plane of the plate.

2. A shock and sound absorbing unit for cushioning the rebound of the type bars of typewriters according to claim 1, wherein the cushion supporting elements at the upper ends of the arcuate edge ofthe plate are in the form of eyes embracing the ends of the cushioning pad.

3. A shock-and sound absorbing unit for cushioning the rebound of the type bars of typewriters according to claim 1, wherein the cushion supporting elements at the intermediate part of the arcuate edge include a trough-shaped part for receiving the bottom portion of the cushioning pad.

4. A shock and sound absorbing unit for cushioning the rebound of the type bars of typewriters according .to claim 1, wherein the arcuate cushioning pad is tubular and has an internal stifiening rod of the same radius of curvature as thebore of the tubular member and is adhesively secured thereto, and wherein the outer surface of the tubular cushioning pad is adhesively secured to the said end and intermediate cushioning upporting members.

GI'USEPPE PREZIOSO. 

